Engine Control Module and Sensor Locations

The Engine Control Module (ECM) is also known as the Powertrain Control Module (PCM) or the Engine Control Unit (ECU).

The main responsiblity of this controller is to get information from sensors and run certain actuators. In the case of any errors, the ECU shows a check engine light on your dashboard.

We will discuss where and why sensors are placed in certain positions and give some insight as to how or what the sensors sense. If you are a DIY person, then you could even open up the sensors yourself and clean them for optimum signals to reach your ECU.

ECM | Source

Powertrain Control

Engine Control Module:

No matter how complicated, you'll find the sensors below in any EFI engine:

Engine coolant temperature

Air temperature

Barometric pressure/manifold absolute pressure

Mass air flow

Idle air controller

Crankshaft

Camshaft

Throttle position

Oxygen

Knock

Engine coolant temperature sensor | Source

Location of ECT sensor | Source

Engine Coolant Temperature Sensor (ECT)

Like humans, a vehicle needs to maintain a specific temperature in order to function properly. Too cold, and the vehicle will drink too much petrol. Too hot and the head gasket could leak. Coolant is a liquid used in the vehicles radiator of the car to maintain the temperature at which the engine can perform at its optimum.

The engine coolant temperature sensor simply tells the car's computer (ECM) the current temperature of the vehicle. When the temperature of the coolant reaches between 75 and 95 degrees (depending on the manufacturer specifications), the ECM instructs the radiator fan to turn on and start cooling down the liquid.

Usually it is located either on the bottom of the radiator, or by follow the top radiator hose towards the engine block. You'll see it on mounted on the engine block.

It can be cleaned using a wire brush when you entirely change your engine coolant (approx. every 80,000 km or 50,000 miles).

Intake air temperature sensor | Source

Location of intake air temperature sensor | Source

Air Temperature Sensor (IAT)

The intake air temperature sensor (IAT) tells the ECM the temperature of the air that is going into the engine. The cooler the air, the better the performance of the engine, which is probably why you might have noticed a difference in the car's performance on a summer night as compared to the day.

It is usually located on the air filter box or the pipe going from the air filter box to the throttle body. Toyota has a MAF and an IAT sensor built in one unit which has five wires located on the air filter box.

It can be cleaned once every six months (depending on dust/pollution), using carb cleaner on an ear cleaner.

Manifold absolute pressure sensor | Source

Location of MAP sensor | Source

BARO/Manifold Absolute Pressure Sensor (MAP)

The baro sensor measures the ambient air pressure, which tells the ECM the current altitude of the vehicle. If you're driving in the mountains you'll need less fuel, because there is less oxygen in the atmosphere and therefore less oxygen in the engine cylinder. The ECM will adjust the fuel injectors "throwing time" or pulse width accordingly.

The map sensor detects the vacuum pressure created inside the intake manifold of the vehicle and sends the engine load information to the ECM. The ECM will adjust the fuel injectors pulse width accordingly.

Note: Baro and MAP sensors look and work in a similar fashion, therefore only one of the two sensors will be found in one engine.

Usually found either bolted on the intake manifold or linked with a vacuum pipe from the intake manifold.

If mounted on intake manifold then should be cleaned every 6 months to 1 year, using carb cleaner (depends on fuel quality where you live; the lower the quality of fuel, the more carbon deposits found). I've had to clean some every three months.

Mass air flow sensor | Source

Location of MAF sensor | Source

Mass Air Flow Sensor

The Mass Air Flow sensor is responsible for measuring the volume of air entering the engine.

The sensor contains a heated sensing element, as shown in the picture above. The temperature of this element has to be kept constant, but is cooled by the air passing through the intake. The MAF sensor produces more current to keep the temperature at the level required by the manufacturer. There is a small computer in the MAF which calculates the internal current flow to heat the element, and by using this figure it can calculate the volume of air going into the engine as well as the air density and temperature. The ECU uses this information to adjust the injector pulse width and spark (ignition) timing.

The MAF Sensor is located either on the air cleaner box or along the pipe going from the air cleaner to the throttle body.

Note: Since the MAF sensor calculates the air density, the engine does not need the MAP or baro sensor readings. Therefore you will not see a MAP or baro sensor in your engine if you have a MAF installed and vice versa.

Can be cleaned with carb cleaner or MAF cleaner spray and ear cleaning bud. Clean if you see dust or carbon deposits.

Idle air control valve (Japanese makes). | Source

Idle air control valve (seen in Hyundai models). | Source

Location of IACV on typical Japanese vehicle. | Source

Idle Air Controller (IACV)

The Idle Air Control Valve (IACV) is responsible for keeping the RPM of the engine steady. The IACV is actually an actuator and not a sensor because it does not supply readings to the ECM, but works on the command of the ECM. I just added this actuator for the DIY enthusiast.

There are two coolant pipes connected to the housing, which you can see on the far right of the picture shown. The black piece shown in the picture is a magnetic actuator which rotates the valve shaft allowing it to open and close as required by the ECM.

Whenever you start your car the IACV will increase the RPM until the coolant temperature sensor (ECT) tells the ECU that the temperature of the engine is up-to the manufacturers specifications. The RPM will then drop down to and remain steady at approx 800 rpm whenever there is an extra load on the engine the idle controller adjusts and compensates for the load applied—for example, switching from park to drive mode in an automatic transmission vehicle, or even when you switch on your air conditioning. You can also adjust the idle speed of the vehicle by loosening the screws on the actuator and rotate the actuator. The default setting of the actuator is normally in the middle.

Located on the throttle body of the vehicle.

Depending on fuel quality, carbon deposits build up and the valve shaft gets stuck resulting in fluctuating RPM signals on the dashboard.

To clean remove the black magnetic actuator which will reveal the shaft. Try rotating the shaft with your fingers. If it's a little hard, then use carburetor cleaner and a toothbrush or ear cleaning bud to clean the area of the valve (the two identical rectangular blocks), and check to see if the shaft is easy to rotate. When putting the magnetic sensor back, make sure the rubber O-ring goes on the metal housing and then align the tip of the shaft with the step inside the magnetic sensor. Set the sensor to the mid-position and tighten the screws.

Note: On some vehicles a scanner is required to reset the idle controller once opened.

Throttle position sensor. | Source

Location of throttle position sensor. | Source

Throttle Position Sensor (TPS)

The throttle position sensor (TPS) is linked from the accelerator pedal to the throttle body.

The TPS tells the ECM that the driver is pressing the accelerator pedal. The ECM can also verify this information with the MAP or MAF sensor readings, thus increasing the injector pulse width and spark (ignition) timing.

The TPS is located on the throttle body. Honda has an adjustable TPS sensor and if the initial if your RPM is high and cannot be controlled through the IACV, then the voltage readings of the TPS should be checked. The normal reading for a Honda is close to 0.6V at idle.

I remember playing with the TPS in my friend's car and adjusting his TPS to about 2.5 volts at idle. The result: The became a gas guzzler, consuming about 30 litres of petrol (about 7 gallons) in 30 km (about 18 miles). I guess we learned the hard way.

A newer system for the throttle control came in 2003-2005 and newer models of vehicles, in which a throttle cable is no longer used. A sensor has been placed in the accelerator pedal and the TPS sensor has been replaced with a throttle position motor.

This sensor never requires cleaning. If you do want to clean something on it then just clean the connector points with electrical contact cleaner and a toothbrush. That goes for all the sensors.

Camshaft position sensor. | Source

Camshaft Position Sensor

The camshaft position sensor (CMP) is electro-magnetic and produces a voltage when a metal object moves past. This sensor is responsible for telling the ECM the current position of the camshaft. With this information the ECM can calculate which valve is open and throw fuel through the injector into that cylinder.

This sensor is found on one end of the camshaft, usually on the right side in a front wheel drive car. It's normally not very difficult to access.

Cleaning can be done with a simple dry cloth, but if the oil has been used for too long, a golden-brown stain is left on metal portion of the sensor. In some cases it even comes out black and gooey, which is basically old engine oil turned into sludge. if it's stained then you can use a wire-brush or very fine sandpaper to remove the stain. Make sure no metal bits remain on the sensor. If you need some liquid type material to get some stains off, try WD-40.

Crankshaft position sensor. | Source

Comparison of CMP and CKP sensors. | Source

Crankshaft Sensor (CKP)

This sensor is very similar to the cam position sensor in functionality. It is responsible for telling the ECM the exact location of the crankshaft as well as the RPM (rotations per minute) of the engine. With this information the ECM knows the position of each piston in each cylinder. Using the cam sensor readings, as well as the crank sensor readings, the ECM knows exactly which injector needs to be activated. The synchronization of the cam and crank shafts in an engine is the key to engine performance. This synchronization is also referred to as the engine timing. With the correct timing you will get the fuel and spark delivered at the right time.

It is located at the bottom of the engine somewhere close to the crankshaft.

Cleaning technique for this sensor is exactly the same as the cam sensor. Cleaning once a year is good enough for this sensor.

Note: If your car does not start, a possible reason could be a faulty crank sensor or a broken wire in the crank sensor circuit.

Oxygen sensor. | Source

Oxygen Sensor (O2)

The oxygen sensor (O2) is responsible for "smelling" the exhaust fumes and detecting the oxygen content in order to make sure the engine is consuming the right amount of fuel. The ratio maintained by the ECM is 14.7 parts air to 1 part fuel. This is known as the air/fuel ratio.

There are two types of oxygen sensor: zirconia or titania. These are materials which can detect oxygen and produce a voltage. The voltage range falls between 0.1V to 0.9V.

I normally use a vehicle scanner to check the maximum and minimum readings of the oxygen sensor. If I see both peaks, then I know the sensor is working fine. If the voltage max is 0.8 then I open up the sensor for cleaning. Sometimes the sensor produces a constant voltage but does not fluctuate. This generally means the sensor needs to be replaced.

Knock sensor. | Source

Knock Sensor

The knock sensor contains a piezoelectric crystal. This crystal is able to detect mechanical stress and produces a voltage when the car knocks or pings. Under heavy acceleration, it sends signals to the ECM and the ECM retards the ignition timing to compensate for the knocking, which in effect protects the pistons and rings from damage.

Knocking also occurs when using low-grade fuel and having the knock sensor allows you to use different grade fuels without causing engine damage.

This sensor is normally bolted onto the main-body of the engine in the most difficult and awkward positions. Lucky this sensor never requires cleaning.

What Happens if One of These Sensors Fails?

If a sensor fails and gives abnormal readings, for example a coolant temperature sensor giving a constant reading of -40o, then the ECM goes into fail-safe mode. This means it basically ignores the values of the sensor at fault and tries to either calculate the value of the failed sensor or assumes a constant reading so the vehicle can keep running. Some faliures like a crank sensor or a MAF sensor will result in the vehicle not starting at all.

Comments

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Author

Irfan 4 weeks agofrom Adelaide, Australia

@Rahul : please give more details. I'll try to help as much as I can.

@Billy : sometimes simply unhooking doesn't work. You might have to put a wire to connect both points on the grip you removed to get it to work. Depends on the circuit used in your car. Try putting in a jumper wire and see if the fans work.

BILLY 4 weeks ago

MY COOLENT FANS WONT COME ON. I unhooked my temperature sensor and they didn't come on then I hooked them back up and turned AC on and they still won't come on changed relays and checked fuses they are all good just wondering what the problem could be?

Rahul jha 4 weeks ago

Hello sir,

I have a problem my Skoda fabia is late staring problem. Would u like to help how to fix this problem.

Author

Irfan 7 weeks agofrom Adelaide, Australia

Hi Geven,

You will need to get your key programmed to work with the immobiliser of the vehicle. Look for someone who does key programming in your area.

Author

Irfan 8 weeks agofrom Adelaide, Australia

Hi mark,

Try checking the map/baro sensor grip first to see that it's connected properly. Secondly check to make sure there are no air leaks in the intake system. There is also an o-ring on the map/baro sensor ... make sure the sensor sits tight in it's place. If all good and problem persists then you may have to replace the sensor.

It would be better if you can find a similar vehicle and change the map sensor to see that it takes the problem away before purchasing a new one.

Let me know if the problem persists after all this.

Author

Irfan 8 weeks agofrom Adelaide, Australia

hi simon,

i'm guessing your problem will be in the MAF sensor or the MAP sensor. I would advise to get the car scanned with a diagnostic tool to confirm; then replace the sensor.

does the block senser have an impact in the runing of the engine if its not connected?

Mr Fixer 3 months ago

Yes there is a fan control module sensor in vw golf make 3, 4 & 5 too that senses when the coolant is hoter and needed cooling, and will automatically toggle from low radiator fan spin to medium or high depending on the current temperature of the coolant present in the radiator.. This sensor is mounted right at top conner driver side of the radiator. And if it goes bad will stop the the radiator.

It has the tendency of kick starting the radiator fan and shutting it down based on instructions from the ECU.

It also has the tendency of kick starting your radiator fan even when your engine has shut down for a while due to incomplete cooling cycle required for the health of your engine.

ABBA BONYO 7 months ago

Keep it up,and all this said here are true.

Author

Irfan 9 months agofrom Adelaide, Australia

@zibusiso : I have not heard of a module sensor before. There is a temperature sensor attached to the body near the hose coming from the radiator and some cars (like honda civic) have a second temperature sensor on the radiator. There is a thermostat valve which allows the colder water to flow into the engine but no module sensor.

zibusiso 9 months ago

is there something called a module sensor for VW Golf 4 meant to cool down the car in cases where it is overheating.

Md.Akram Hossain 10 months ago

No doubt that, it's a very intellectual explanation. I am highly pleased to the better analysis of automotive sensing components. hoping that I will get latest information in future also. Have a good days. Allah hafej.

Best regards.

Akram

Author

Irfan 12 months agofrom Adelaide, Australia

@abu hasssan : thanks for stopping by... :)

@jethro : thank you... :)

Author

Irfan 12 months agofrom Adelaide, Australia

hi Abinash

Newer cars a motor fixed with the throttle body. An additional sensor is placed under the accelerator pedal known as the accelerator pedal position sensor which controls the throttle body motor.

Nothing happens if you only have a MAF ... if you don't have a MAF you will have a separate MAP and Air Temperature sensor to get those readings. The TPS value will come from either the TPS sensor or the Accelerator sensor.

At the end of the day these values are required by the ECU therefore it will have to be given one way or the other so that further calculations can be made on how much fuel to deliver in the injectors etc.

abu hasssan 12 months ago

thank you

Abinash 13 months ago

Do all cars have a TPS as well as a MAF sensor. So what happens if my car only has a MAF sensor?

Sorry I didn't ask the question clearly. Is it possible to get readings from ECM? For ex, coolant temperature, intake air temperature, ambient temperature, engine temperature, engine rpm etc... If yes, what kind of devices can be attached to get the readings from ECM?

Raj 21 months ago

I wanted to know that is it possibld to get reading from ECM?

Author

Irfan 21 months agofrom Adelaide, Australia

@Bresmen : Check for air leaks.

bresmen 21 months ago

I have 2005 chevrolet classic when this power begins to raise and lower the rpm needle

Author

Irfan 2 years agofrom Adelaide, Australia

For automatic transmission vehicles 1000 rpm is normal. 800 is for manual transmissions.

Boubker 2 years ago

hi I have a Audi A4 b8 diesel the rpm stay on 1000 when the car is on park what could be thank you

Author

Irfan 2 years agofrom Adelaide, Australia

@winwin : it's sluggish because of an air leak. Make sure the piping and airbox is sealed properly. Any kind of air leak will make it less responsive.

If it's in safe mode then disconnect the battery terminals for 10seconds then fasten them on again. It will erase all the previous codes.

did you wash the throttle and IACV using carb cleaner? maybe something is stuck (carbon). maybe that's why nothing changes.

if throttle is clean then adjust the IACV valve a little. it should lower the rpm.

Also check with scanner to see if there is any engine code. sometimes the check engine light does not work (the electricians here who don't know how to fix the light cut the wire of the light to get paid).

If you have whatsapp then send me your number through my profile and can help you there.

Bashar Alkhateeb 2 years agofrom Amman, Jordan

The engine turn off when the temperature reaches 70 and the rpm start playing with himself

I reset the adjustment on the throttle but nothing changes!!!

Author

Irfan 2 years agofrom Adelaide, Australia

Bashar,

The ECU should do it by its own if nothing was touched before replacing it. First check to see the ECT is working properly using the scanner (fan will switch on and off at the correct times) ... If the RPM is high after the new installation then YES, bring it down using the adjustment on the throttle.

Bashar Alkhateeb 2 years agofrom Amman, Jordan

Do i need to reset the rpm after i change the ECT??

Author

Irfan 2 years agofrom Adelaide, Australia

Not sure about the Chevy but there is an inertia switch which cuts fuel supply incase of an accident. That could be the cause.

p keshav 2 years ago

Could be your vvti sensor a had a similar problem once replaced, the problem was solved

Qasim 2 years ago

I have a 2005 Chevy Malibu classic with a 2.2 ecotehch enine.II have replaced my fuel pump and filter and now I have no psi to the fuel injectors so the car wont start.Is there a reset for this car or do I have to have it reset via computer?

Dorota 2 years ago

Ignition module works for me if it gets too hot, it makes it tough to start. There suhlod be a heat conducting gel under the module, I have no idea how long it is supposed to last, but it would be a quick and cheap fix if all you had to do was clean off the old gel and add some new stuff.

Author

Irfan 2 years agofrom Adelaide, Australia

No problem at all. I look forward to seeing the data. Try to take the following if possible.

Screenshot 1: on idle

Screenshot 2: Rev the engine like you are racing (full throttle) so you get a good min and max range of all the sensors.

Screenshot 3: put foot on pedal and keep engine on 1500 rpm for 30s then record.

edsonsapnu 2 years ago

Thank you so much arksys for spending time with me,i really appretiate it...

I will disregard CAT and thermostat if that so..ECM i open it but i don't smell if it is smell burnt i will do check again the ecm or smell the chips or borrow ecm to other car and put it in for testing...yes i had a scan tool i will also send it to you the flight record if possible..

Again,thank you so very much...

Author

Irfan 2 years agofrom Adelaide, Australia

most of the things seem correct. do you have a scanner? if yes then post the results or email me through the link on my profile page.

clogged catalytic cannot be the problem... when it's clogged then fuel consumption gets very high and becomes very difficult to get the car to move (lack of power). we normally break the CAT block here because the fuel quality is very bad and a new CAT will get blocked in 6 months - 1 year.

damaged thermostat valve will cause bubbles in the reserve coolant container when you drive the car for too long... you can also check the thermostat valve by taking off the radiator cap and watch the water flow when the engine is warm.

one common problem we have with corolla (1NZ-FE) here is that the main computer chips get burnt and require replacement. If you have access to another similar vehicle then i would suggest you take the main ECM and try it in your car for testing. if you don't have access to a similar car then open the ECM and you will see 4 similar computer chips on the main board. smell the chips to see if it is burnt. if yes then get those two chips replaced.

edsonsapnu 2 years ago

Hello arksys,i did to switch 1&2- 3&4 injectors it is still the same.ive already check for inj leaks but not found any leaks,also check for vacuum hoses leak found none, i had a .007"intake- .009" ex. For valve clearance,already clean the ff: cam,crank,maf,iac but still the same. Also check fuel pressure got ok.

Short history for this engine,

Newly overhauled before i performed overhauling the engine was consume 1L a week because it is blowby,then it was totally got dead because of overheat..

Do you think is it possible for clogged Catalytic or damage termostat?

Author

Irfan 2 years agofrom Adelaide, Australia

yes seems like injectors are the problem... try changing the injectors from cylinder 1&2 to 3&4 ... the smell of petrol must shift with it. if it does shift then you have faulty injectors ... if it remains in cylinder 1&2 then check your cam sensor.

edsonsapnu 2 years ago

The first start rpm reach about 1500 then drop to 1000 in 2-3 sec.rpm is not fluctuate it steady in 1000 but very rough idle.and 1 thing i notice every time i pull out S PLUGS it smell gas(1&2 cylinder only) seems like not burning very well..is it possible a injector leak?

Author

Irfan 2 years agofrom Adelaide, Australia

Is engine Rpm normal when cold?

When you start the engine the rpm should be around 2000 then it will drop to about 950 or 800 depending on manual or automatic transmission. If the needle is smooth then iac is fine.

Have you checked the tappets/valve clearance?

Another way to check is to see the response over 90km/h. If it accelerates slowly above 90km/h then you may need to adjust. Another sign is high fuel consumption.

If it's auto valve adjustment system then you need to remove the head and grind the shims. Keep this as your last option.

First Try cleaning the cam sensor. It is directly related to the injectors. While you are cleaning the cam sensor the also clean the crank sensor.

You will notice a brown film stuck on the sensor. Spray carb cleaner on a cloth then wipe the metal portion.

edsonsapnu 2 years ago

I had a trouble with toyota altis 1zzfe engine.,every time the engine is cold had very rough idle but after a few minutes when engine reach the normal temp it is very smooth.first i suspected the MAF and i already clean it but nothing changes,second the ECT already replaced still nothing,now i am looking and focus with my iac but 1 thing i am confuse,when i put it in drive,turn on ac,turn HL, iac performed verywell..i don't have CEL on my dashboard.but i had a little black smoke in my tail pipe..

Please help to figure it out...thank you in advance..

Author

Irfan 2 years agofrom Adelaide, Australia

I'm glad it helped you edsonsapnu. if you have any problems then feel free to ask. :)

edsonsapnu 2 years ago

This hub is very useful..im a auto mechanic from philippines,every time im in troubleshooting i always open hubpages as a guideline..

2. Carbon stuck in both IACV as well as on the throttle plate. Need to wash using carb cleaner.

3. Air leaks... If you have an air leak in your intake system then the if idle speed goes up.

This is all assuming that your check engine light is off.

yav . Cyprus 2 years ago

what could be causing my 1999 mercedes e240 m112 car to have high idle issues. Car idles at around 1200 revs. If I depress the accelerator even ever so slightly the revs jumps to around 2300 and stays there until I switch off the car. When restarted car idles again around 1200revs. Just like others Iam also mystified with modern ecu controlled cars. Thx in advance and keep up the good work

Author

Irfan 3 years agofrom Adelaide, Australia

Thanks quambar.pakistan.

I will try to write up some sensor testing procedures soon and faults associated with those sensors.

I have tuned a couple of friends cars the way I've mentioned above and they all said it's the best drive they have ever had in that car. The 2 hours work is worth it.

Quamber. Pakistan 3 years ago

I have been servicing older engines for a long time now and was very familiar with all diesels starting from MB 636 all the way to the 616 and petrol engines from DKW F11 2 stroke to the later mitsubeshi engines.

Completely in the fog with the ecm system. Although I had the system fairly maped out but this artiical has sorted things out completely.

It would be nice to know how to check the individual sensors for their working condition.

Great work. A lot of thanks are due for the information contained

Author

Irfan 3 years agofrom Adelaide, Australia

too much fuel delivery ... get your crank and cam sensors cleaned and check IACV. its throwing too much fuel into the system which is causing it to shut down and not start. once the fuel has evaporated it starts again.

jan 3 years ago

I have a Jetta 4 1.6 when is cold it start one kick but after idling few minute the rev start going up and down and gone off and is not going to start again unless after few hours

Author

Irfan 3 years agofrom Adelaide, Australia

You may have carbon build-up in your idle air control valve... located on the throttle body. Get it washed with Carb Cleaner Spray.

If it still gives troubles look for air leaks.

good luck.

des 3 years ago

When driving my car rpm drops down then back up what could this be and when stopped the car feels like it want to cut off 99 Pontiac grand am SE

Author

Irfan 3 years agofrom Adelaide, Australia

@ishmael : Clean your CRANK and CAM and MAP sensor. Should improve.

@Mayur : I'm not sure of any courses but look online for ASE certification. It's the best or automotive learning.

ISHMAEL 3 years ago

I HAVE A JETTA 4 1.6 2001 MODEL IT TAKES TIME TO START, I CHANGED THE ENGINE ITS DOING THE SAME THING, I HAVE TO SWING FOR LONG, THEN WHEN IT STARTS THERE WILL BE A SMELL OF PETROL, COULD IT BE THE PETROL PUMP??

DOES THE CAR HAVE ANY SENSOR TO TELL THE ENGINE TO START OR NOT, SOMEWHERE ON THE THROTTLE??

Mayur 3 years ago

Hello Friend, I have to join this course where i can do.? where is institute or Classes.....I am related to Technical Automobile Course. please can u give sugession ?

Author

Irfan 4 years agofrom Adelaide, Australia

thanks Lois, i'm halfway through the transmission hub too... will try to find time to finish it soon. ;)

LoisRyan13903 4 years agofrom Upstate NY originally from Long Island

Great article. I have an hour-and-half commute and am getting familiar with the check engine light and the sensors. I'm fines since these are all pretty easy and inexpensive fixes, as long as I don't get any transmission codes

Author

Irfan 4 years agofrom Adelaide, Australia

thanks for your comment khairat. i'm glad you find it helpful. ;)

ali khairat 4 years agofrom Marrakech

Wow this is a very help full article i ve been looking for this information a long time ago. Thanks dud.

Author

Irfan 4 years agofrom Adelaide, Australia

hey michael,

thanks for your comment... the fog isn't as thick as it initially seems to be. I remember when i tried to start learning about engines, i even tried out a course for 2 months ... but not even the teacher gave me the simple breakdown of it all... i had to learn myself through books and on the internet. :)

Author

Irfan 4 years agofrom Adelaide, Australia

hey Roy,

a couple of times i have been stuck on things which turn out to be mechanical issues. annoying but good learning curves. :) thanks for your comment.

Author

Irfan 4 years agofrom Adelaide, Australia

hey michael,

thanks for your comment... the fog isn't as thick as it initially seems to be. I remember when i tried to start learning about engines, i even tried out a course for 2 months ... but not even the teacher gave me the simple breakdown of it all... i had to learn myself through books and on the internet. :)

michael 4 years ago

Just checking out hub pages for the first time and I happened upon this article. When I was young, a long time ago, I did all my own work on cars. As soon as they began to be controlled by ECMs I became totally mystified and unable to do the simplest repairs. Breaking down the system like you did helps me to see through the technological fog..may be I can't work on the system like a pro, but maybe someday i can at least change the bad modules. Good article!

royblizzard 4 years agofrom Austin / Leander, Texas

We had a strange issue with our cad as the knock sensor was detecting a loose motor mount tapping as we were driving an causing the engine to go through all sorts of gyrations and power issues. Once we replaced that motor mount all the issues vanished. LOL who would've thought?

Author

Irfan 4 years agofrom Adelaide, Australia

you're welcome pablo. :)

pablo 4 years ago

just want to say thankyou for the valuavle ,information.

Author

Irfan 4 years agofrom Adelaide, Australia

thanks YGY

YGY 4 years ago

GOOD...

Author

Irfan 5 years agofrom Adelaide, Australia

Thank you Alexander ... the newer vehicles are a lot simpler than the older vehicles, if you have the right equipment and knowledge.

I'm glad you feel well equipped to tackle the newer vehicles now ... If however, you run into any troubles then let me know, i'll be glad to help. :)

This hub is so incredibly useful for me - you did a great job explaining how each piece works and how to test it and so on. I will definitely be checking a few of these components this year because I have a few problems to iron out on my Tahoe. I have previously preferred older vehicles without any computers, but armed with this sort of knowledge, I think I can tackle cars of the 21st century now :-)

Author

Irfan 5 years agofrom Adelaide, Australia

yep ... that's also the concept behind the "cold air intake" which are sold in the aftermarket. the colder the air the higher the density thus containing more oxygen than warm air. i've tried using a cold air intake in my car and have found a noticable difference in accelaration at higher speeds.

joe322 5 years ago

Interesting you note that the cooler it is, the better the engine runs. My physics instructor told us that the greater the difference between the temperatures of the internal versus the external of the engine, the greater the efficiency of the combustion process. That was the first time I had heard this concept until reading your hub. Keep writing these insightful articles and sharing your knowledge! Voted up.